Detonating-velocity recorder.



H. F. METTEGANG.

DETONATING VELOGITY RECORDER.

APPLICATION FILED FEB.9,1906.

91 6,572. Patented Mar. 30, 1909.

7% fN-VENTQR.

Arm 25,

UNITED STATES rarEN'r onion.

Specification of Letters Patent.

Application filed February 1906. Serial No. 300,333.

To all whom it may concern:

Be it known that I, Hans Fnmnmon Mormons-c, subject or" the German Empire, residing at Schlebusc'h, Germany, have in.- rented new and useful Improvements in Detonating-Velocity Recorders, of which the foliowing is a specification; i

In particular my invention relates to that kind of electro clironographic apparatus, in which, by the combination of a spark-inductor with an isochronally moved drum or paper-strip and other parts, small intervals of time, as in particular combustion or detonation-periods, are graphically recorded by rows of blank points produced on the sootrovered or otherwise prepared surface of the said drum or strip. I

The object of my invention is to realize by the combination of a plurality of sparkinductors with a drumor strip-indicator and a detonation controlled inductor ciramt-breaker or weakener (both) of accordingiy modified construction-the electrochronographic determination of very small intervals of time like combustion or detol1ation-velocit-ies bymeans of recording on the indicator-drum or strip a plurality of point-rows which are distant one from the other in the direction of the height of the indicator-drum or the width of the recording strip. By such new constructional measures and corresponding new electr'o chronogra'phic method it iis made possible to determine combustion or detonation-velocities with a precision and reliability which is much superior to the effect realized by the use of elect-ro-magnetic chronographs (of the Leboulang-type or the like), in which the moment of demagnetization or falling of the recording armature never exactly coincides with the moment of the intcrruption or weakening of the electro-magnet-circuit produced in 'de endence from the beginning'or end of the etonation and by far superior also to results obtained with spark-inductor-apparatus (of the Siemens type and others similar to it), which contain only one spark-inductor producing only one line of recording points and in which the periods of weakening or breaking of the primary inductor-circuit, id est the beginning or endin of the detonation, are not always distinct y marked.

Referring -to the annexed drawing showing a front-view of a preferred constructional form of the electro-chronograpnic apparatusembodying the present invention, I I

Patented March so, 1909.

sista-nce-means (in orderto reduce the tensionwhich is usually employed for electriclighting, which, however, istoo high for an electro chronograph as represented. on the drawing). To the said lamp-rows the electric energy is supplied by means of. the shown. wires branched from the main condue-tor I; and with theother wires 1 P, I departing from the said lamp-rows connection is made with the exploding tube F containing the cartridges filled with the explosive substance or mixture the combustionvelocity of which is tobe determined. The priming of said cartridges is progressively effected in any known way avoiding inter-- vals. between consecutive detonations c'tl est preferably by means of electric sparks.

By the detonation of the cartridges which are to be tested interruption or weakening" is successively produced'in the branch-circuits which are formed in. departure from the. eXploding-tube-wires l P, I in such a manner that they include the primary-coils of the three represented spark-inductors E E E which, of course, are made without magnet-cores, the wire-connection of the said primary coils with the second main .conductor K being clearly shown on the drawing. From the secondary coils of the sparkinductors E E E are branched out the wires L L L .and M M, M. The firstsaid of these wires are connected to the sparking-points D, while the last-said are attached to the indicator-frame N, so that by said wirescurrent is always fed also to v the inetallicdrum C which is carried by the said frame by means of journals permitting of its easy rotation, as it is known from other electro-phronographs O is an arm carried by the frame N, the vertical position of which may be varied by means of an adjusting screw-spindle and to which are secured the sparking points D, the connection of which to the secondary coils of the sparkinductors by means of the wires L L L has already been mentioned; Each of the three sparking points is made and fixed upon an end-plate of thearm O in anyknown manner which permits of more or less ap proaching the sparking-points toward the drum 0 with the necessary precision; For the purpose of producing the rotation of the drum 0, the uniformity of which is a known necessity, an electro-motor A is shown in the general disposition ememple' gratz'a given on the annexed drawing. The shaft P of the armature of said motor A is coupled, as shown, to a spindle journaled in the frame N, and from this spindle the driving movement is transmitted to the axis of the indicating drum by means of bevel-wheel-gearing. To make possible a permanent exact control of the uniformity of the drum-rotation the motor A is shown connected with a bifluid-tachometer B, the driving spindle of which is directly coupled to the right projecting end of the motor-shaft P,

In general the function and operation of the improved electrode chronograph having the afore-stated main constructional features are the'following: In proportion as I the cartridges to be tested are progressively subjected to the detonation, an interruption or weakening effect is produced in the current flowing through the primary coils of the spark-inductorsE E E. In conse-,

quence a corresponding influence being exerted also upon the current emanating from the secondary coils of the spark-inductors,

" id est the increase of tension necessary for causing the spark to traverse the sparkin gap between the points D and the drum 5 being produced, on the latter three rows of blank points, as shown for instance on the drawing at H, are formed, such rows being distanced from each other in vertical direction. Thus a graphic record of the detonation-velocity is obtained, the accuracy of which is by far superior to the quality of the records obtainable by the use of known spark-inductor-chronographs on account of the following two facts:

Firstly the formation (with regard to the recording-progress) of transverse distances between the point-rows resulting from the use of three spark-inductors in combination with three sparking points enables the tester to read from the lndicator-drum the exact beginning and end of the graphic equivalent of the combustion-periods, such accurate measurement being rarely realized when known spark-inductor-chronographs are used, on the drums of which the rows of points are recorded in one and the same circumferential-or not step-forming line It is known that such imperfect recording is caused by the fact that between two series of recording-points electrically produced in one circumferential line the space which is intended to indicate the end and beginning of the detonation phases is often imperfectly pendent also from the fact that a fairlyhigh voltage can be used for the primary inductor-current and that the sparking points can be brought to a very short distance from the indicating drum, whereby each of the three point-diagrams traced one beneath the other are obtained of fair length and distinctness. The same conditions, when. established in known chronographs having only one spark-inductor, are prejudicious or not available at all, inasmuch as, in measuring exceedingly small intervals of time like detonation-periods, the rigorous space between two consecutive rows of points often does not produce itself, as the last points of one row prove'to be covered by the points of the beginning of the following row. To the different chronographic old and new eflects exposed in the foregoing correspond on an average the following point records:

Three inductor chronograph embodying the present invention: i

u u n a e a n s n:

Single inductor: chronograph of the Siemens type or the like:

Desired rigorous diagram of two point-rows Continuous false record of the sam diagram a D u a I e u a u e I the exploding tube .F and are to be tested in order to determine the velocity of the corn bustion of their charge.

It may be imagined that-after having introduced into the exploding tube F the 13 cartridges the combustion velocity of which wires being introduce is to be tested the above-mentioned connection between the wires P, P, I and the said cartridges may be effected by three thin and rigid wires, which we call registering needles as forming the firstly acting transmitting means forthe graphic record and which are disposed in sucha manner that they pass for instance across the exploding tube F atthe middles of the 1st, 7th and" tain uniform length or charge, so that, when they are introduced, in the number of 1.3, into the said exploding tube provided with the six needle-holes, the middles of the 1st, 7th and 13th cartridge are in perfect opposition to the afore-said couples of holes, that is to say that the needles engaged into these holes penetrate the three recording-cartridges at or near the bisection oints of their lengthas it-is a proximately 5 own also on the drawing. f such bisectional penetration of the critical cartridges is not to be realized, it is necessary at least for an exact recordin result that the said cartridges are traverse uniform distance from their front or back end-faces.

Now we suppose that the trial-cartridges are ignited from the first at the left side, to that effect electrical i iting or exploding into the free end of the said first cartridge or close by that end, as it is represented also on the drawing at the left end of the exploding tube left being said in the sense of a person viewing the drawing). f

The ignition of the first trial-cartridge reaching also all the other cartrid es with great velocity, during the la se of several ractional parts of a second 't 1e combustion or explosion of all the 13 cartridges will take place in the exploding tube F. It is in p a quite mechanical Way, that is by fusion or rupture caused by the heat er-the vehemence of the explosion, that the "thre'e registering needles engaged into the 1st, 7th and 13th cartridge'are destroyed one after the other and that in accordance the electric current arriving from the wires I 1 I is intercepted 1n its W297 to the primary coils of the inductors E, E, by such interruption the induction sparks being correspondingly caused to flash at the interruption points of the wires L, L, L and M M M conduct-.

ing the induced current from the secondary by the registering needles at a to the nature of their formation. it is obvious also, that the three rows of dots coils of the inductors. The said interruotion points are constituted, as it is alrea y stated in the general part of this specification, by the minute Intervals formed be tween the metallicrecordi-ng drum C, coveredwith soot or with a diagram-papersheet, and the sparking points D.

As tothe particular conditions of electric connection they are preferably established and made .use of in accordance with the drawing because all diagrams of the questionable kind are usually read from top to foot, so that the highest point Dis in connection with M that of the middle with- M" and the lowest with M, while, for the rest, the indices of the reference letters are app'osed in ascending order from left to right and from bottom to top.

Now it must be duly remembered that before the beginning of anelectrochronographic measuring experiment an isoj ch-ronical rotation is always im arted to the drum C of a certain great spec determined by trial or experience. By such rotation it :is effected that the blank 'tracerproduced in the soot-coating of the drum C by a s ark flashing against the same from one of the sparking points D is elon ated and cannot form, in consequence a sing e dot.- Thus the said trace is rather constituted by a series of dots or points and cannot assume the form of a line of a certain small length, because,

as it is known, the induction sparks oscillate or flicker, so to speak, without exception, such unsteadlness be1ng a phenomenon due Moreover which are recorded on the drum- C one below lowest inductor E as the first recording needle destroyed after the ignitlon is that Zwhich is connected to the wire I and put across the first trial cartridge, and the destruction of which causes, by means of the conducting wires L M the passage of the said spark from the highest point D to the drum (J. Now, if the diagram represented on the drum C is approximately exact there is still a certain reason for the question why, according to the conditions shown on the drawing, the recording of the middle row of dots may have already begun before the u per-most dot-row is finished and why t e same relationship is to be stated with re ard to the undermost and median row of dots. Theanswer to such question'is the following: The interval lyin between the destruction of the 1st and 751 or between the 7th and 13th cartrid e is shorter or can be shorter than the space 0 time during which the discharge of sparks takes place at each of the inductors from the moment on which the primary current fed to the said inductors is interrupted. Practically thislapse of time is depending also on the quality of the manutacture of the'inductor, whereby, as it is known, considerable influence is exerted also on the immediate starting of the secondary current, a fact bearing more or less also on the electrochronographic recording results. Moreover it may be stated also that the entire course or formation of the dot-rows, that is to say their right-hand or terminal part, is of little interest for the recording result. It is essential only to obtain a distinct and exact graphic determination of the initial' or starting (left hand) portion of the three rows of points-viz, of the relative distance of the initial ends of the said three graphic notations, such initial recording result being realized in the electrochronograph embodying the present invention to a degree of perfection which. renders entirely impossible the confusion of the divisional diagrams as being recorded one below the other, As to the said distance of the initial points of the divisional diagrams it is evidently to he understood in the sense of the rotation oi? the drum G, and if it is supposed for instance that 1. millimeter of the peripherical advance of the said drum (moving isoch-' ronally as it has already been stated) corresponds to an interval of a seconds, and if it is furthermore supposed that in the diagram the distance of the left ends of the uppermost and middle recording trace has been determined to be 95 millimeters and that the analogous end-distance between the middie and the undermost recordingv trace is measured to he 3/ millimeters, the average amount of the combustion time 2? of one of n cartridges introduced into the exploding bar-- seconds,

In the case of m-zy this formula is simplified to t seconds.

The chronometric result obtained in. this manner by means or the present invention may easily be recognized as being very exact and reliable to a degree never attained by the use of other apparatus which have been constructed hitherto for the same purpose.

lt is obvious that all dispositions and constructive details explained in the foregoing about the improved chronograph may he modified in any possible way, provided that such alterations do not essentially interfere with the functional features of the new differential recording method. lln this regard it may be particularly stated that, instead of disposing three inductors, more or only two may he established, to such modified number ng a plurality of blank point-rows distant one from the other in a sense transverse to the length of such rows.

In testimony whereof I have signed. my name to this specification in the presence of two subscribing witnesses.

HANS Flllllllltlllll METTEGANS.

Witnesses:

VVILLIAM ESSENWEIN, PETER LIEBER. 

